The pathogenesis of lyme neuroborreliosis: from infection to inflammation

Co-infection dynamics of B. afzelii and TBEV in C3H mice: insights and implications for future research

Ticks are important vectors of disease, particularly in the context of One Health, where tick-borne diseases (TBDs) are increasingly prevalent worldwide. TBDs often involve co-infections, where multiple pathogens co-exist in a single host. Patients with chronic Lyme disease often have co-infections with other bacteria or parasites. This study aimed to create a co-infection model with Borrelia afzelii and tick-borne encephalitis virus (TBEV) in C3H mice and to evaluate symptoms, mortality, and pathogen level compared to single infections. Successful co-infection of C3H mice with B. afzelii and TBEV was achieved. Outcomes varied, depending on the timing of infection. When TBEV infection followed B. afzelii infection by 9 days, TBEV symptoms worsened and virus levels increased. Conversely, mice infected 21 days apart with TBEV showed milder symptoms and lower mortality. Simultaneous infection resulted in mild symptoms and no deaths. However, our model did not effectively infect ticks with TBEV, possibly due to suboptimal dosing, highlighting the challenges of replicating natural conditions. Understanding the consequences of co-infection is crucial, given the increasing prevalence of TBD. Co-infected individuals may experience exacerbated symptoms, highlighting the need for a comprehensive understanding through refined animal models. This study advances knowledge of TBD and highlights the importance of exploring co-infection dynamics in host-pathogen interactions.

Serum neurofilament light chain associates with symptom burden in Lyme neuroborreliosis patients: a longitudinal cohort study from Norway

OBJECTIVES

Serum neurofilament light chain (sNfL), an indicator of neuronal damage, is increasingly recognized as a potential biomarker for disease activity in neurodegenerative disorders. In this study, we wanted to investigate sNfL as a prognostic marker in a large, well-defined population of 90 patients with Lyme neuroborreliosis (LNB). In addition, we sought to explore associations between symptoms and sNfL levels during the acute phase of LNB.

MATERIALS AND METHODS

Patients diagnosed with definite or possible LNB were recruited from a double-blinded, placebo-controlled, multi-center trial, in which the participants were randomly assigned to 2 or 6 weeks of oral doxycycline treatment. The sNfL levels were measured using a single molecule array assay at both diagnosis and 6-month follow-up, and analysed against clinical parameters, variations in symptom burden and long-term complaints as assessed by a composite clinical score.

RESULTS

At the time of diagnosis, approximately 60% of the patients had elevated sNfL levels adjusted for age. Notably, mean sNfL levels were significantly higher at diagnosis (52 pg/ml) compared to 6 months after treatment (12 pg/ml, p < 0.001), when sNfL levels had normalized in the majority of patients. Patients with objective signs of spinal radiculitis had significantly higher baseline sNfL levels compared to patients without spinal radiculitis (p = 0.033).

CONCLUSION

Our findings suggest that sNfL can serve as a biomarker for peripheral nerve tissue involvement in the acute phase of LNB. As found in an earlier study, we confirm normalization of sNfL levels in blood after treatment. We found no prognostic value of acute-phase sNfL levels on patient outcome.

Optic nerve involvement in patients with Lyme neuroborreliosis: an electrophysiological study

PURPOSE

The aim of this neurophysiological study was to retrospectively analyze visual evoked potentials (VEPs) acquired during an examination for diagnosing optic nerve involvement in patients with Lyme neuroborreliosis (LNB). Attention was focused on LNB patients with peripheral facial palsy (PFP) and optic nerve involvement.

METHODS

A total of 241 Czech patients were classified as having probable/definite LNB (193/48); of these, 57 were younger than 40 years, with a median age of 26.3 years, and 184 were older than 40 years, with a median age of 58.8 years. All patients underwent pattern-reversal (PVEP) and motion-onset (MVEP) VEP examinations.

RESULTS

Abnormal VEP results were observed in 150/241 patients and were noted more often in patients over 40 years (p = 0.008). Muscle/joint problems and paresthesia were observed to be significantly more common in patients older than 40 years (p = 0.002, p = 0.030), in contrast to headache and decreased visual acuity, which were seen more often in patients younger than 40 years (p = 0.001, p = 0.033). Peripheral facial palsy was diagnosed in 26/241 LNB patients. Among patients with PFP, VEP peak times above the laboratory limit was observed in 22 (84.6%) individuals. Monitoring of patients with PFP and pathological VEP showed that the adjustment of visual system function occurred in half of the patients in one to more years, in contrast to faster recovery from peripheral facial palsy within months in most patients.

CONCLUSION

In LNB patients, VEP helps to increase sensitivity of an early diagnostic process.

Paretic complications of tick-borne encephalitis and Lyme neuroborreliosis in the Czech Republic: Characteristics and clinical outcome

Tick-borne encephalitis (TBE) and Lyme neuroborreliosis (LNB), the most common tick-borne diseases of the central nervous system in Central Europe, are frequently associated with pareses. The aim of this study was to characterise paretic complications in patients with TBE and LNB, including their severity, persistence and impact on the patients' quality of life. Our retrospective observational study included patients with aseptic CNS infection due to TBE virus or Borrelia burgdorferi sensu lato. Paretic complications were evaluated in the acute phase and the patients were followed up until complete regression or long-term stabilisation of any neurological deficit. The severity of the neurological deficit was graded according to the modified Rankin Scale (mRS). A total of 823 patients (582 with TBE, 241 with LNB) was included. Paretic complications were diagnosed in 63 TBE patients (10.8 %) and in 147 LNB patients (61.0 %). In TBE, the most common neurological deficit was brachial plexus paresis in 21 patients (33 %) and bulbar symptoms in 18 patients (29 %). In LNB patients, facial nerve palsy was the most frequent neurological deficit (117patients; 79.6 %), followed by lower limb paresis in 23 patients (15.6 %). Forty-nine TBE patients and 134 LNB paretic patients completed follow-up. Paresis resolved within 3 weeks in 16 TBE patients (33 %) and 53 LNB patients (39.5 %), but the proportion of patients with paresis persisting for more than 12 months was significantly higher in TBE (34.7 vs. 3.7 %, p < 0.001). The mean mRS was significantly higher in TBE paretic patients compared to LNB (p < 0.001). Paretic complications are significantly more common in LNB than in TBE but pareses associated with TBE last longer than in LNB and considerably reduce the quality of life of patients. Prevention remains the only way to influence the long-term motor deficits of TBE.

Case presentation and management of Lyme disease patients: a 9-year retrospective analysis in France

Introduction

Lyme borreliosis (LB) is the most common vector disease in temperate countries of the northern hemisphere. It is caused by Borrelia burgdorferi sensu lato complex.

Methods

To study the case presentation of LB in France, we contacted about 700 physicians every year between 2003 and 2011. An anonymous questionnaire was established allowing the collection of 3,509 cases. The information collected was imported or directly entered into databases and allowed identifying variables that were validated in a multiple correspondence analysis (MCA).

Results

Sixty percent of the cases were confirmed, 10% were probable, 13.5% doubtful, 10.2% asymptomatic seropositive and 6.3% were negative. The clinical manifestations reported were cutaneous (63%), neurological (26%), articular (7%), ocular (1.9%) and cardiac (1.3%). Almost all patients were treated. When focusing more particularly on confirmed cases, our studies confirm that children have a distinct clinical presentation from adults. There is a gender effect on clinical presentation, with females presenting more often with erythema migrans or acrodermatitis chronica atrophicans than males, while males present more often with neurological signs or arthritis than females.

Discussion

This is the first time that a comprehensive study of suspected Lyme borreliosis cases has been conducted over several years in France. Although we were not able to follow the clinical course of patients after treatment, these results suggest the interest of refining the questionnaire and of following up a cohort of patients over a sufficiently long period to obtain more information on their fate according to different parameters.

Direct Detection of Borrelia Species in Tissues

Among the controversies in Lyme disease is the potential for Borrelia spirochetes to persist after guideline-directed antimicrobial therapy. Direct detection of the spirochetes has been essential to explore this phenomenon, given that the infection is often occult and infrequently observed in blood and other body fluids. In addition, the role of spirochetal infection has been examined in the etiology of neurodegenerative diseases through detection in affected tissues. In this chapter, we describe methodology to specifically identify Borrelia DNA, RNA, and intact organism (via protein) in tissue for studies of Lyme Borreliosis.

Concurrent Infection of the Human Brain with Multiple Borrelia Species

Lyme disease (LD) spirochetes are well known to be able to disseminate into the tissues of infected hosts, including humans. The diverse strategies used by spirochetes to avoid the host immune system and persist in the host include active immune suppression, induction of immune tolerance, phase and antigenic variation, intracellular seclusion, changing of morphological and physiological state in varying environments, formation of biofilms and persistent forms, and, importantly, incursion into immune-privileged sites such as the brain. Invasion of immune-privileged sites allows the spirochetes to not only escape from the host immune system but can also reduce the efficacy of antibiotic therapy. Here we present a case of the detection of spirochetal DNA in multiple loci in a LD patient's post-mortem brain. The presence of co-infection with Borrelia burgdorferi sensu stricto and Borrelia garinii in this LD patient's brain was confirmed by PCR. Even though both spirochete species were simultaneously present in human brain tissue, the brain regions where the two species were detected were different and non-overlapping. The presence of atypical spirochete morphology was noted by immunohistochemistry of the brain samples. Atypical morphology was also found in the tissues of experimentally infected mice, which were used as a control.

The influence of physiological and pathological perturbations on blood-brain barrier function

The blood-brain barrier (BBB) is located at the interface between the vascular system and the brain parenchyma, and is responsible for communication with systemic circulation and peripheral tissues. During life, the BBB can be subjected to a wide range of perturbations or stresses that may be endogenous or exogenous, pathological or therapeutic, or intended or unintended. The risk factors for many diseases of the brain are multifactorial and involve perturbations that may occur simultaneously (e.g., two-hit model for Alzheimer's disease) and result in different outcomes. Therefore, it is important to understand the influence of individual perturbations on BBB function in isolation. Here we review the effects of eight perturbations: mechanical forces, temperature, electromagnetic radiation, hypoxia, endogenous factors, exogenous factors, chemical factors, and pathogens. While some perturbations may result in acute or chronic BBB disruption, many are also exploited for diagnostic or therapeutic purposes. The resultant outcome on BBB function depends on the dose (or magnitude) and duration of the perturbation. Homeostasis may be restored by self-repair, for example, via processes such as proliferation of affected cells or angiogenesis to create new vasculature. Transient or sustained BBB dysfunction may result in acute or pathological symptoms, for example, microhemorrhages or hypoperfusion. In more extreme cases, perturbations may lead to cytotoxicity and cell death, for example, through exposure to cytotoxic plaques.

Cerebrospinal fluid levels of the macrophage-specific biomarker sCD163 are diagnostic for Lyme neuroborreliosis: an observational cohort study

OBJECTIVES

We aimed to investigate levels of the macrophage-specific marker, sCD163, in cerebrospinal fluid and plasma in patients with Lyme neuroborreliosis. We tested the diagnostic value of CSF-sCD163 and ReaScan-CXCL13 and analyzed if plasma-sCD163 could monitor treatment response.

METHODS

An observational cohort study: Cohort 1-Cerebrospinal fluid from adults with neuroborreliosis (n=42), bacterial meningitis (n=16), enteroviral meningitis (n=29), and controls (n=33); Cohort 2-Plasma from 23 adults with neuroborreliosis collected at diagnosis, three, and six months. sCD163 was determined using an in-house sandwich ELISA. ReaScan-CXCL13 measured semiquantitative concentrations of CXCL13, cut-off ≥250 pg/ml diagnosed neuroborreliosis. Receiver Operating Characteristics analyzed the diagnostic strength. A linear mixed model including follow-up as categorical fixed effect analyzed differences in plasma-sCD163.

RESULTS

CSF-sCD163 was higher in neuroborreliosis (643 µg/l) than in enteroviral meningitis (106 µg/l, p<0.0001) and controls (87 µg/l, p<0.0001), but not bacterial meningitis (669 µg/l, p=0.9). The optimal cut-off was 210 µg/l, area under the curve (AUC) 0.85. Combining ReaScan-CXCL13 with CSF-sCD163 increased AUC to 0.89. Plasma-sCD163 showed little variation and was not elevated during the 6 months of follow-up. Conclusion CSF-sCD163 is diagnostic for neuroborreliosis with an optimal cut-off of 210 µg/l. Combining ReaScan-CXCL13 with CSF-sCD163 increases AUC. Plasma-sCD163 cannot monitor treatment response.

Diving into the complexity of the spirochetal endoflagellum

Spirochaetes, a phylum that includes medically important pathogens such as the causative agents of Lyme disease, syphilis, and leptospirosis, are in many ways highly unique bacteria. Their cell morphology, subcellular organization, and metabolism reveal atypical features. Spirochetal motility is also singular, dependent on the presence of periplasmic flagella or endoflagella, inserted subterminally at cell poles and not penetrating the outer membrane and elongating outside the cell as in enterobacteria. In this review we present a comprehensive comparative genomics analysis of endoflagellar systems in spirochetes, highlighting recent findings on the flagellar basal body and filament. Continued progress in understanding the function and architecture of spirochetal flagella is uncovering paradigm-shifting mechanisms of bacterial motility.

3D blood-brain barrier-organoids as a model for Lyme neuroborreliosis highlighting genospecies dependent organotropism

Lyme neuroborreliosis (LNB), a tick-borne infection caused by spirochetes within the Borrelia burgdorferi sensu lato (s.L.) complex, is among the most prevalent bacterial central nervous system (CNS) infections in Europe and the US. Here we have screened a panel of low-passage B. burgdorferi s.l. isolates using a novel, human-derived 3D blood-brain barrier (BBB)-organoid model. We show that human-derived BBB-organoids support the entry of Borrelia spirochetes, leading to swelling of the organoids and a loss of their structural integrity. The use of the BBB-organoid model highlights the organotropism between B. burgdorferi s.l. genospecies and their ability to cross the BBB contributing to CNS infection.

Exploration of the induced cytokine responses in European Lyme neuroborreliosis: A longitudinal cohort study

Lyme neuroborreliosis (LNB) is a prevalent tick-borne disease in Europe caused by Borrelia burgdorferi sensu lato complex. Slightly suppressed induced Th1- and Th17-responses are seen at diagnosis. The induced immune response following antibiotic therapy is unknown. We hypothesized that the immune responses normalize after completing antibiotic treatment. An observational longitudinal cohort study investigating the induced immune response in adult patients with LNB at diagnosis, three and six months after treatment. Whole blood was added to three TruCulture® (Myriad RBM, Austin, USA) tubes each containing one stimulation. An additional TruCulture® tube was without stimulation representing the in vivo activation of blood immune cells. Nine cytokines were measured using Luminex (LX200, R&D Systems, BIO-Teche LTD). Changes in immune response were analyzed with linear mixed model including follow-up as categorical fixed effect. A total of 21 patients with 55 samples were included. All had clinical improvement, but 5/21 patients reported residual symptoms after six months. The non-induced release of IL-17A and IL-1β increased significantly from diagnosis to six month follow-up. Six months after treatment only IFN-α and TNF-α were below the reference range. Minor variations in the induced immune responses were seen during the study period. Th1- and Th17-responses continued to be low with low IFN-γ, IL-12p40, and IL-17A in multiple stimulations. Overall little dynamic was observed. The changes in the cytokine responses are most likely not linked to LNB pathogenesis and our results do not support the implementation of TruCulture® in the diagnostics or follow-up of LNB.

The CXCL13/CXCR5 Immune Axis in Health and Disease—Implications for Intrathecal B Cell Activities in Neuroinflammation

The chemokine C-X-C- ligand 13 (CXCL13) is a major B cell chemoattractant to B cell follicles in secondary lymphoid organs (SLO) that proposedly recruits B cells to the cerebrospinal fluid (CSF) during neuroinflammation. CXCR5, the cognate receptor of CXCL13, is expressed on B cells and certain T cell subsets, in particular T follicular helper cells (Tfh cells), enabling them to follow CXCL13 gradients towards B cell follicles for spatial proximity, a prerequisite for productive T cell–B cell interaction. Tfh cells are essential contributors to B cell proliferation, differentiation, and high-affinity antibody synthesis and are required for germinal center formation and maintenance. Circulating Tfh cells (cTfh) have been observed in the peripheral blood and CSF. Furthermore, CXCL13/CXCR5-associated immune activities organize and shape adaptive B cell-related immune responses outside of SLO via the formation of ectopic lymphoid structures in inflamed tissues, including the central nervous system (CNS). This review summarizes the recent advances in our understanding of the CXCL13/CXCR5 immune axis and its role in vaccination, autoimmunity, and infection with a special focus on its relevance for intrathecal B cell activities in inflammatory CNS diseases.

The Mechanistic Pathways of Periodontal Pathogens Entering the Brain: The Potential Role of Treponema denticola in Tracing Alzheimer’s Disease Pathology

Alzheimer’s Disease (AD) is a complex neurodegenerative disease and remains the most common form of dementia. The pathological features include amyloid (Aβ) accumulation, neurofibrillary tangles (NFTs), neural and synaptic loss, microglial cell activation, and an increased blood–brain barrier permeability. One longstanding hypothesis suggests that a microbial etiology is key to AD initiation. Among the various periodontal microorganisms, Porphyromonas gingivalis has been considered the keystone agent to potentially correlate with AD, due to its influence on systemic inflammation. P. gingivalis together with Treponema denticola and Tannerella forsythia belong to the red complex consortium of bacteria advocated to sustain periodontitis within a local dysbiosis and a host response alteration. Since the implication of P. gingivalis in the pathogenesis of AD, evidence has emerged of T. denticola clusters in some AD brain tissue sections. This narrative review explored the potential mode of spirochetes entry into the AD brain for tracing pathology. Spirochetes are slow-growing bacteria, which can hide within ganglia for many years. It is this feature in combination with the ability of these bacteria to evade the hosts’ immune responses that may account for a long lag phase between infection and plausible AD disease symptoms. As the locus coeruleus has direct connection between the trigeminal nuclei to periodontal free nerve endings and proprioceptors with the central nervous system, it is plausible that they could initiate AD pathology from this anatomical region.

Lyme neuroborreliosis: known knowns, known unknowns

Lyme borreliosis affects the nervous system in three principal ways-mononuclear cell meningitis, cranial neuropathies and radiculoneuropathies-the last a broad term encompassing painful radiculopathy, unifocal and multifocal peripheral nerve involvement. Diagnostic tools have been significantly refined-including improved peripheral blood and CSF serodiagnostics-and much has been learned about the interactions between the causative pathogen and the nervous system. Despite these advances in our understanding of this disease, a broad range of other disorders continue to be misattributed to nervous system Lyme borreliosis, supported by, at best, limited evidence. These misattributions often reflect limited understanding not only of Lyme neuroborreliosis but also of what constitutes nervous system disease generally. Fortunately, a large body of evidence now exists to clarify many of these issues, establishing a clear basis for diagnosing nervous system involvement in this infection and, based on well performed studies, clarifying which clinical disorders are associated with Lyme neuroborreliosis, which with non-neurologic Lyme borreliosis, and which with neither.

Effectiveness of antibiotic treatment in children with Lyme neuroborreliosis - a retrospective study

Background

Lyme neuroborreliosis (LNB) is a tick-borne infection caused by the spirochete Borrelia burgdorferi sensu lato complex with various neurological manifestations. The recommended treatment for LNB in Swedish children has been intravenous ceftriaxone 50–100 mg/kg × 1 (< 8 years of age) or oral doxycycline 4 mg/kg × 1 (≥ 8 years of age) for 10–14 days. Studies on adult LNB patients have shown equal efficacy for ceftriaxone and doxycycline, but no such studies have been conducted on pediatric LNB patients. The aim of this study is to retrospectively evaluate clinical outcome in children with LNB who have received intravenous ceftriaxone or oral doxycycline.

Results

Clinical and laboratory data from three previously conducted prospective studies on children with LNB (1998–2014) were retrospectively analyzed. A total of 321 children (1–19 years of age), who received antibiotic treatment for definite LNB or possible LNB, were included. Clinical outcome at the 2-month follow-up (recovery/non-recovery) was evaluated using Chi² test and logistic multivariate regression analysis. Out of 321 LNB patients, 194 children (60%) had received ceftriaxone and 127 children (40%) had received doxycycline. When comparing clinical outcome between treatment groups, no difference was found (p = 0,217). Results did not change when incorporating relevant clinical and laboratory data into the logistic multivariate regression analysis.

Conclusion

In this large retrospective study, no difference in clinical outcome was found, independent of age, when comparing children who received ceftriaxone with those who received doxycycline, supporting an equal effectiveness for treatment of LNB pediatric patients. However, future randomized comparative treatment studies are warranted for evaluation of efficacy of antibiotic treatment in pediatric LNB patients.

Lyme Disease: A Role for Coenzyme Q10 Supplementation?

Lyme disease results from a bacterial infection following a bite from an infected tick. Patients are initially treated with antibiotics; however, in cases where antibiotic treatment is delayed, or when patients do not respond to antibiotic treatment, fatigue may develop alongside problems affecting the nervous system, cardiovascular system, and joints. It is thought that most of the damage to these tissues results from the excessive inflammatory response of the host, involving a self-reinforcing cycle of mitochondrial dysfunction, oxidative stress and inflammation. In this article, we review the potential role of supplementary coenzyme Q10 (CoQ10) in mediating the pathogenic mechanism underlying Lyme disease, on the basis of its role in mitochondrial function, as well as its anti-inflammatory and antioxidant actions.

The special role of CXCL13 in Lyme neuroborreliosis: a case report

The diagnosis of chronic lyme neuroborreliosis can be a challenge even for experienced neurologists. The clinical picture may be multifaceted, including polyradiculitis to cranial nerve palsies, meningitis, encephalomyelitis, encephalopathy and peripheral neuropathy. We report on a patient presenting with basal leptomeningoencephalitis associated with vasculopathy where the chemokine CXCL13 in cerebrospinal fluid played an important diagnostic role.

Case Report: An Isolated Abducens Palsy Secondary to Lyme Disease

SIGNIFICANCE

Lyme disease can have widespread and long-lasting systemic implications, and ocular manifestations of Lyme disease may be the only presenting symptoms of infection. As such, eye care providers can play a critical role in facilitating diagnosis and treatment of this disease.

PURPOSE

This case report describes an isolated sixth nerve palsy secondary to Lyme disease, which is a rare neuro-ophthalmic presentation. This report emphasizes the importance of considering Lyme disease in the setting of atypical nerve palsies to allow for appropriate treatment and prevent long-term complications of untreated disease.

CASE REPORT

A 63-year-old man presented with new onset, painful diplopia for one day and was diagnosed with a right sixth nerve palsy. His medical history was significant for relapsing polychondritis with associated ocular complications, so his nerve palsy was presumed secondary to a flare of his systemic disease. However, secondary to complaints of new night sweats, infectious etiologies were also considered. The patient was initially treated with oral steroids with no improvement in his diplopia after being admitted to the hospital for further work-up. Approximately one week after presentation, Lyme titers returned positive and the diagnosis was revised to abducens palsy secondary to Lyme disease. The patient's nerve palsy rapidly resolved after oral therapy with doxycycline.

CONCLUSIONS

Lyme disease is a systemic illness that can have widely varying manifestations, including ocular findings. Eye involvement may be the only presenting symptom, allowing eye care providers to serve an important role in disease recognition and management.

Acute Lyme neuroborreliosis with transient aphasia – Case report and review of current knowledge

Lyme borreliosis (LB) is a tick-borne infectious disease, endemic in the Northern hemisphere, with a polymorphic clinical spectrum (cutaneous, articular, and neurologic involvement). The variability of clinical manifestations poses LB as a diagnostic challenge. We describe a case of acute Lyme neuroborreliosis (LNB) in an adult female with a history of recent travel in Europe. There are few reports of acute LNB presenting as encephalitis in the literature. Suspicion for the diagnosis and prompt treatment seems to have a positive impact on patient outcomes.

Borrelia burgdorferi Co-Localizing with Amyloid Markers in Alzheimer's Disease Brain Tissues

BACKGROUND

Infections by bacterial or viral agents have been hypothesized to influence the etiology of neurodegenerative diseases.

OBJECTIVE

This study examined the potential presence of Borrelia burgdorferi spirochete, the causative agent of Lyme disease, in brain autopsy tissue of patients diagnosed with either Alzheimer's (AD) or Parkinson's diseases.

METHODS

Brain tissue sections from patients with age-matched controls were evaluated for antigen and DNA presence of B. burgdorferi using various methods. Positive Borrelia structures were evaluated for co-localization with biofilm and AD markers such as amyloid and phospho-tau (p-Tau) using immunohistochemical methods.

RESULTS

The results showed the presence of B. burgdorferi antigen and DNA in patients with AD pathology and among those, one of them was previously diagnosed with Lyme disease. Interestingly, a significant number of Borrelia-positive aggregates with a known biofilm marker, alginate, were found along with the spirochetal structures. Our immunohistochemical data also showed that Borrelia-positive aggregates co-localized with amyloid and anti-phospho-tau markers. To further prove the potential relationship of B. burgdorferi and amyloids, we infected two mammalian cell lines with B. burgdorferi which resulted in a significant increase in the expression of amyloid-β and p-Tau proteins in both cells lines post-infection.

CONCLUSION

These results indicate that B. burgdorferi can be found in AD brain tissues, not just in spirochete but a known antibiotics resistant biofilm form, and its co-localized amyloid markers. In summary, this study provides evidence for a likely association between B. burgdorferi infections and biofilm formation, AD pathology, and chronic neurodegenerative diseases.

Comprehensive Mapping of the Cell Response to Borrelia bavariensis in the Brain Microvascular Endothelial Cells in vitro Using RNA-Seq

Borrelia bavariensis can invade the central nervous system (CNS) by crossing the blood-brain barrier (BBB). It is predicted that B. bavariensis evokes numerous signaling cascades in the human brain microvascular endothelial cells (hBMECs) and exploits them to traverse across the BBB. The complete picture of signaling events in hBMECs induced by B. bavariensis remains uncovered. Using RNA sequencing, we mapped 11,398 genes and identified 295 differentially expressed genes (DEGs, 251 upregulated genes and 44 downregulated genes) in B. bavariensis challenged hBMECs. The results obtained from RNA-seq were validated with qPCR. Gene ontology analysis revealed the participation of DEGs in a number of biological processes like cell communication, organization of the extracellular matrix, vesicle-mediated transport, cell response triggered by pattern recognition receptors, antigen processing via MHC class I, cellular stress, metabolism, signal transduction, etc. The expression of several non-protein coding genes was also evoked. In this manuscript, we discuss in detail the correlation between several signaling cascades elicited and the translocation of BBB by B. bavariensis. The data revealed here may contribute to a better understanding of the mechanisms employed by B. bavariensis to cross the BBB.

Lyme neuroborreliosis in pediatrics: A retrospective, descriptive study in southwest France

BACKGROUND

The neurological effects of Lyme borreliosis in children are varied and their clinical progression is not widely reported in the French literature. We carried out a retrospective study to describe the clinical characteristics of Lyme neuroborreliosis in children in southwest France and their clinical progression at 6 months.

METHODS

This study was carried out at Toulouse University Hospital during the period 2006-2017 using patient records. Case definition was based on the combined French clinical and laboratory diagnostic criteria.

RESULTS

In total, 26 children were included. The median age was 8 years (4-14 years). The different neurological symptoms reported were: meningoradiculitis (62%), which was usually associated with facial palsy (54%); isolated facial palsy (15%); isolated meningitis (8%); polyradiculoneuritis (4%); benign intracranial hypertension (4%) and myelomeningoradiculitis (4%). The most common functional symptoms were headaches (54%), the perception of asthenia (42%), neck pain (27%), and a loss of appetite (19%). Patients with laboratory meningitis (84%) often had no signs of meningism or headaches (38%).

CONCLUSION

The majority of the cases involved meningoradiculitis but other, less common, neurological conditions have been described. The clinical signs suggestive of meningitis are not very marked and might delay the diagnosis.

Bilateral Facial Nerve Palsy in a Young Woman From West Bengal: Do Not Forget Lyme Neuroborreliosis

Borrelia burgdorferi can affect the nervous system in various ways, which can generate significant confusion and dilemma regarding diagnosis. From India, a country until recently known to be a nonendemic zone for Lyme disease, several cases and one study of Lyme neuroborreliosis have been published. The aim of this study was to describe a young woman with bilateral facial nerve palsy as the presenting manifestation of Lyme neuroborreliosis. We herein report a case of a lactating woman with acute onset progressive ascending flaccid tetraparesis that was preceded by a misdiagnosed bilateral facial nerve palsy. She was finally diagnosed to be a case of acute Lyme neuroborreliosis, which responded favorably to intravenous and orally administered antibiotics. The possibility of Lyme neuroborreliosis should be considered more often from now on because in the last year four cases with the kindred clinical syndrome have been described from a so-called "nonendemic zone."

Clinical and laboratory evidence of Lyme disease in North India, 2016-2019

BACKGROUND

Lyme disease is endemic to parts of the Americas, Europe and Asia. However, only a handful of sporadic cases have been reported from India. In this study, we systematically evaluated the clinical and epidemiological features of Lyme disease in North India.

METHOD

All samples were tested by using the standard two-tiered testing algorithm (STTA). Paired serum and cerebrospinal fluid (CSF) were used for demonstrating Borrelia burgdorferi specific intrathecal IgG antibody synthesis (AI). In addition, a commercial tick-borne bacterial flow chip (TBFC) system and a real-time PCR were also used to detect Borrelia species and Anaplasma phagocytophilum in patients who were positive by STTA.

RESULTS

The diagnosis of Lyme disease was confirmed in 18 (7.14%) of the 252 clinically suspected cases by STTA. Neurological involvement was reported in 14 (77.78%) patients, whereas joint and heart involvement was reported in five (27.78%) and three (16.67%) patients, respectively. Lymphocytic pleocytosis (median 37.5 cells/mm³; range 12-175 cells/mm³) in the CSF was seen in 11 of 14 Lyme neuroborreliosis (LNB) patients. Intrathecal production of Borrelia specific IgG antibodies was demonstrated in 9 (64.28%, n = 14) patients, a highly specific finding for neuroborreliosis. Two patients (11.11%) were also found to be co-infected with human granulocytic anaplasmosis.

CONCLUSIONS

The results of this study show clinical and laboratory evidence of endemic Lyme disease in North India and thus, highlight the importance for travel medicine practitioners and physicians to evaluate for Lyme disease in patients with compatible symptoms and a history of travel to tick risk areas.

Long COVID or Post-acute Sequelae of COVID-19 (PASC): An Overview of Biological Factors That May Contribute to Persistent Symptoms

The novel virus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a pandemic of coronavirus disease 2019 (COVID-19). Across the globe, a subset of patients who sustain an acute SARS-CoV-2 infection are developing a wide range of persistent symptoms that do not resolve over the course of many months. These patients are being given the diagnosis Long COVID or Post-acute sequelae of COVID-19 (PASC). It is likely that individual patients with a PASC diagnosis have different underlying biological factors driving their symptoms, none of which are mutually exclusive. This paper details mechanisms by which RNA viruses beyond just SARS-CoV-2 have be connected to long-term health consequences. It also reviews literature on acute COVID-19 and other virus-initiated chronic syndromes such as post-Ebola syndrome or myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) to discuss different scenarios for PASC symptom development. Potential contributors to PASC symptoms include consequences from acute SARS-CoV-2 injury to one or multiple organs, persistent reservoirs of SARS-CoV-2 in certain tissues, re-activation of neurotrophic pathogens such as herpesviruses under conditions of COVID-19 immune dysregulation, SARS-CoV-2 interactions with host microbiome/virome communities, clotting/coagulation issues, dysfunctional brainstem/vagus nerve signaling, ongoing activity of primed immune cells, and autoimmunity due to molecular mimicry between pathogen and host proteins. The individualized nature of PASC symptoms suggests that different therapeutic approaches may be required to best manage care for specific patients with the diagnosis.

Lyme Neuroborreliosis: Mechanisms of B. burgdorferi Infection of the Nervous System

Lyme borreliosis is the most prevalent tick-borne disease in the United States, infecting ~476,000 people annually. Borrelia spp. spirochetal bacteria are the causative agents of Lyme disease in humans and are transmitted by Ixodes spp ticks. Clinical manifestations vary depending on which Borrelia genospecies infects the patient and may be a consequence of distinct organotropism between species. In the US, B. burgdorferi sensu stricto is the most commonly reported genospecies and infection can manifest as mild to severe symptoms. Different genotypes of B. burgdorferi sensu stricto may be responsible for causing varying degrees of clinical manifestations. While the majority of Lyme borreliae-infected patients fully recover with antibiotic treatment, approximately 15% of infected individuals experience long-term neurological and psychological symptoms that are unresponsive to antibiotics. Currently, long-term antibiotic treatment remains the only FDA-approved option for those suffering from these chronic effects. Here, we discuss the current knowledge pertaining to B. burgdorferi sensu stricto infection in the central nervous system (CNS), termed Lyme neuroborreliosis (LNB), within North America and specifically the United States. We explore the molecular mechanisms of spirochete entry into the brain and the role B. burgdorferi sensu stricto genotypes play in CNS infectivity. Understanding infectivity can provide therapeutic targets for LNB treatment and offer public health understanding of the B. burgdorferi sensu stricto genotypes that cause long-lasting symptoms.

Proteomic Analysis of Rhesus Macaque Brain Explants Treated With Borrelia burgdorferi Identifies Host GAP-43 as a Potential Factor Associated With Lyme Neuroborreliosis

Background

Lyme neuroborreliosis (LNB) is one of the most dangerous manifestations of Lyme disease, but the pathogenesis and inflammatory mechanisms are not fully understood.

Methods

Cultured explants from the frontal cortex of rhesus monkey brain (n=3) were treated with live Borrelia burgdorferi (Bb) or phosphate-buffered saline (PBS) for 6, 12, and 24 h. Total protein was collected for sequencing and bioinformatics analysis. In addition, changes in protein expression in the explants over time following Bb treatment were screened.

Results

We identified 1237 differentially expressed proteins (DEPs; fold change ≥1.5 or ≤0.67, P-value ≤0.05). One of these, growth-associated protein 43 (GAP-43), was highly expressed at all time points in the explants. The results of the protein-protein interaction network analysis of DEPs suggested that GAP-43 plays a role in the neuroinflammation associated with LNB. In HMC3 cells incubated with live Bb or PBS for 6, 12, and 24 h, real-time PCR and western blot analyses confirmed the increase of GAP-43 mRNA and protein, respectively.

Conclusions

Elevated GAP-43 expression is a potential marker for LNB that may be useful for diagnosis or treatment.

Are other tick-borne infections overlooked in patients investigated for Lyme neuroborreliosis? A large retrospective study from South-eastern Sweden

In Europe, the hard tick Ixodes ricinus is considered the most important vector of human zoonotic diseases. Human pathogenic agents spread by I. ricinus in Sweden include Borrelia burgdorferi sensu lato (s.l.), Anaplasma phagocytophilum, Rickettsia helvetica, the recently described Neoehrlichia mikurensis, Borrelia miyamotoi, tick-borne encephalitis virus (TBEV), and Babesia spp. (Babesia microti, Babesia venatorum and Babesia divergens). Since these pathogens share the same vector, co-infections with more than one tick-borne pathogen may occur and thus complicate the diagnosis and clinical management of the patient due to possibly altered symptomatology. Borrelia burgdorferi s.l., TBEV and B. miyamotoi are well-known to cause infections of the central nervous system (CNS), whereas the abilities of other tick-borne pathogens to invade the CNS are largely unknown. The aim of this study was to investigate the presence and clinical impact of tick-borne pathogens other than B. burgdorferi s.l. in the cerebrospinal fluid (CSF) and serum samples of patients who were under investigation for Lyme neuroborreliosis (LNB) in a tick-endemic region of South-eastern Sweden. CSF and serum samples from 600 patients, recruited from the Regions of Östergötland County, Jönköping County and Kalmar County in South-eastern Sweden and investigated for LNB during the period of 2009-2013, were retrospectively collected for analysis. The samples were analysed by real-time PCR for the presence of nucleic acid from B. burgdorferi s.l., B. miyamotoi, A. phagocytophilum, Rickettsia spp., N. mikurensis, TBEV and Babesia spp. Serological analyses were conducted in CSF and serum samples for all patients regarding B. burgdorferi s.l., and for the patients with CSF mononuclear pleocytosis, analyses of antibodies to B. miyamotoi, A. phagocytophilum, spotted fever group (SFG) rickettsiae, TBEV and B. microti in serum were performed. The medical charts of all the patients with CSF mononuclear pleocytosis and patients with positive PCR findings were reviewed. Of the 600 patients, 55 (9%) presented with CSF mononuclear pleocytosis, 13 (2%) of whom had Borrelia-specific antibodies in the CSF. One patient was PCR-positive for N. mikurensis, and another one was PCR-positive for Borrelia spp. in serum. No pathogens were detected by PCR in the CSF samples. Four patients had serum antibodies to B. miyamotoi, four patients to A. phagocytophilum, five patients to SFG rickettsiae, and six patients to TBEV. One patient, with antibodies to SFG rickettsiae, had both clinical and laboratory signs suggestive of a current infection. Nine patients had serum antibodies to more than one pathogen, although none of these was assessed as a current co-infection. We can conclude from this study that tick-borne co-infections are uncommon in patients who are being investigated for suspected LNB in South-eastern Sweden, an area endemic for borreliosis and TBE.

Ceftriaxone and Doxycycline induced Seroconversion in Previously Seronegative Patient with Clinically Suspected Disseminated Lyme Disease: Case Report

We present a case of middle-aged woman whose health problems began 3 months after a registered tick bite in endemic area of Lyme borreliosis. First symptoms included fatigue, chills, cervical lymphadenopathy, neck pain and stiffness. Patient was afebrile. Lyme disease was excluded due to lack of erythema migrans and negative enzyme immunoassay test results for anti-Borrelia antibodies. During the next few months, her condition was getting worse and symptoms were accompanied with brain fog, dizziness, palpitations, irregular menstrual cycles, insomnia, panic attacks, headaches, and muscle aches. This led to multiple medical tests and examinations, but the diagnosis failed to be established. Finally, after occurrence of paresthesia and weakness of leg muscles, clinical diagnosis of disseminated Lyme borreliosis with nervous system involvement was suspected and antibiotic therapy was initiated. After the second dose of Ceftriaxone, patient got fever and her condition worsened. However, Ceftriaxone therapy was continued for a total of 5 days and was followed by 4 weeks of doxycycline therapy. Upon completion of antibiotic therapy, high specific anti-Borrelia antibodies were detected by Western blot and SeraSpot. Appearance of anti-Borrelia antibodies, in contrast to negative test results performed immediately before the therapy started, indicated seroconversion. 18 months after the therapy, patient was completely without the symptoms. This paper emphasizes importance of clinical evaluation of Lyme disease and shows a unique case of seroconversion in patient with symptoms of disseminated Lyme disease. Seroconversion was likely triggered by release of lipoproteins and other immunogenic molecules from Borrelia once the bacterial die-off began due to antibiotic therapy.

Case Report: Ascending Myelo-Encephalitis after a Penetrating Injury to the Foot: An Atypical Case of Neuromelioidosis

Organisms penetrate the central nervous system (CNS) via three routes. The commonest is the hematogenous route, and other routes include contiguous or penetrating injury or rarely via retrograde axoplasmic route. Although the axoplasmic highway is often used by viruses, only a few bacteria are known to penetrate the CNS via this route. We present a 57-year-old man who developed a penetrating injury while working in a field. Over the next 4 months, he developed pain at the site of the poorly healing wound, which ascended up the right leg and presented as a conus-cauda syndrome. Magnetic resonance imaging (MRI) showed an enhancing intradural intramedullary enhancing lesion in the conus on the right side with cord edema from D11 to L1 level. Extensive evaluation was negative, and he continued to progress to holocord myelitis and developed bilateral corticospinal tract lesions ("tractopathy") in the brain stem and internal capsule. He died after developing a right-sided cerebritis with mass effect. Tissue biopsy from the brain at the time of decompressive craniectomy grew Burkholderia pseudomallei and confirmed a diagnosis of neuromelioidosis (NM). We reviewed the literature for NM, its variable presentations, and the concept of an "infectious tractopathy" and imaging findings which could generate suspicion of this entity.

Abdominal pain as first manifestation of lyme neuroborreliosis in children, case report and review of literature

Background

Lyme neuroborreliosis can cause a variety of neurological manifestations. European children usually present facial nerve palsy, other cranial nerve palsies and aseptic meningitis.

Case presentation

We hereby report a case of Lyme neuroborreliosis in a 9-year-old boy with abdominal pain as first symptom and subsequent onset of attention deficit and ataxia. Diagnosis was made by detection of specific antibody in both serum and cerebrospinal fluid with neuro-radiological images suggestive for this infectious disease. A 12-months follow-up was performed during which no relevant neurological sequelae were revealed.

Conclusion

This case report shows that abdominal radiculitis, although extremely rare, could be the first manifestation of early Lyme neuroborreliosis in pediatric patients. Pediatricians must consider Lyme disease in the differential diagnosis of abdominal pain of unknown origin in children, especially in countries where the infection is endemic.

Symptom Clusters and Functional Impairment in Individuals Treated for Lyme Borreliosis

Context: Persistent fatigue, pain, and neurocognitive impairment are common in individuals following treatment for Lyme borreliosis (LB). Poor sleep, depression, visual disturbance, and sensory neuropathies have also been reported. The cause of these symptoms is unclear, and widely accepted effective treatment strategies are lacking.

Objectives: To identify symptom clusters in people with persistent symptoms previously treated for LB and to examine the relationship between symptom severity and perceived disability.

Methods: This was a retrospective chart review of individuals with a history of treatment of LB referred to The Dean Center for Tick-Borne Illness at Spaulding Rehabilitation Hospital between 2015 and 2018 (n = 270) because of persistent symptoms. Symptoms and functional impairment were collected using the General Symptom Questionnaire-30 (GSQ-30), and the Sheehan Disability Scale. Clinical tests were conducted to evaluate for tick-borne co-infections and to rule out medical disorders that could mimic LB symptomatology. Exploratory factor analysis was performed to identify symptom clusters.

Results: Five symptom clusters were identified. Each cluster was assigned a name to reflect the possible underlying etiology and was based on the majority of the symptoms in the cluster: the neuropathy symptom cluster, sleep-fatigue symptom cluster, migraine symptom cluster, cognitive symptom cluster, and mood symptom cluster. Symptom severity for each symptom cluster was positively associated with global functional impairment (p < 0.001).

Conclusion: Identifying the interrelationship between symptoms in post-treatment LB in a cluster can aid in the identification of the etiological basis of these symptoms and could lead to more effective symptom management strategies.

Key Message: This article describes symptom clusters in individuals with a history of Lyme borreliosis. Five clusters were identified: sleep-fatigue, neuropathy, migraine-like, cognition, and mood clusters. Identifying the interrelationship between symptoms in each of the identified clusters could aid in more effective symptom management through identifying triggering symptoms or an underlying etiology.

Imaging of Lyme Neuroborreliosis: A Pictorial Review

Lyme neuroborreliosis is a common feature of Borrelia burgdorferi infection (as a neurological manifestation occurring in 10%–15% of all Lyme disease cases) and may involve any part of the nervous system, and its coverings, but usually manifests as lymphocytic meningitis, cranial neuritis, and/or radiculoneuritis. This review describes the imaging findings in Lyme neuroborreliosis: the focal point is on the manifestations of involvement visible on brain and spine imaging.

The Lyme disease bacterium, Borrelia burgdorferi, stimulates an inflammatory response in human choroid plexus epithelial cells

The main functions of the choroid plexus (CP) are the production of cerebral spinal fluid (CSF), the formation of the blood-CSF barrier, and regulation of immune response. This barrier allows for the exchange of specific nutrients, waste, and peripheral immune cells between the blood stream and CSF. Borrelia burgdorferi (Bb), the causative bacteria of Lyme disease, is associated with neurological complications including meningitis-indeed, Bb has been isolated from the CSF of patients. While it is accepted that B. burgdorferi can enter the central nervous system (CNS) of patients, it is unknown how the bacteria crosses this barrier and how the pathogenesis of the disease leads to the observed symptoms in patients. We hypothesize that during infection Borrelia burgdorferi will induce an immune response conducive to the chemotaxis of immune cells and subsequently lead to a pro-inflammatory state with the CNS parenchyma. Primary human choroid plexus epithelial cells were grown in culture and infected with B. burgdorferi strain B31 MI-16 for 48 hours. RNA was isolated and used for RNA sequencing and RT-qPCR validation. Secreted proteins in the supernatant were analyzed via ELISA. Transcriptome analysis based on RNA sequencing determined a total of 160 upregulated genes and 98 downregulated genes. Pathway and biological process analysis determined a significant upregulation in immune and inflammatory genes specifically in chemokine and interferon related pathways. Further analysis revealed downregulation in genes related to cell to cell junctions including tight and adherens junctions. These results were validated via RT-qPCR. Protein analysis of secreted factors showed an increase in inflammatory chemokines, corresponding to our transcriptome analysis. These data further demonstrate the role of the CP in the modulation of the immune response in a disease state and give insight into the mechanisms by which Borrelia burgdorferi may disseminate into, and act upon, the CNS. Future experiments aim to detail the impact of B. burgdorferi on the blood-CSF-barrier (BCSFB) integrity and inflammatory response within animal models.

The potential for CXCL13 in CSF as a differential diagnostic tool in central nervous system infection

Introduction: Central nervous system (CNS) infections can be life-threatening and are often associated with disabling sequelae. One important factor in most CNS infections is a timely pathogen-specific treatment. The diagnostic methods available, however, do not always reach a satisfying sensitivity and specificity. In these cases, there is need for additional diagnostic biomarkers. Chemokines represent potential candidates as biomarkers, since they are an important pillar of the host immune response. The aim of this review is to discuss the diagnostic potential of cerebrospinal fluid (CSF) CXCL13 in patients with CNS infections. Areas covered: Data were obtained from a literature search in PubMed up to October 2019. This review focusses on articles on the potential of CXCL13 as a diagnostic tool. The majority of identified studies aimed to characterize its role in two diseases, namely Lyme neuroborreliosis and neurosyphilis. Expert opinion: CSF CXCL13 has a significant potential as a diagnostic and monitoring add-on marker in Lyme neuroborreliosis. Differences in study design, control groups and clinical parameters between studies, however, affect sensitivity, specificity and cutoff values, underlining the need of further studies to address these issues and pave the way for a generalized clinical practice.

Specificity and Diagnostic Utility of Cerebrospinal Fluid CXCL13 in Lyme Neuroborreliosis

Background

Demonstration of intrathecal production of Borrelia-specific antibodies (ITAb) is considered the most specific diagnostic marker of Lyme neuroborreliosis (LNB). Limitations include delayed detectability in early infection and continued presence long after successful treatment. Markers of active inflammation—increased cerebrospinal fluid (CSF) leukocytes, protein, and CXCL13—provide nonspecific markers of active infection. To assess the utility of CSF CXCL13, we measured its concentration in 132 patients with a broad spectrum of neuroinflammatory disorders, including LNB.

Methods

CSF CXCL13 was measured by immunoassay. Spearman rank correlation test was performed to explore its relationship to conventional markers of neuroinflammation and Borrelia-specific ITAb production.

Results

In non-LNB neuroinflammatory disorders, CSF CXCL13 elevation correlated with CSF immunoglobulin G (IgG) synthesis and leukocyte count. In LNB, CXCL13 concentration was far greater than expected from overall CSF IgG synthesis, and correlated with Borrelia-specific ITAb synthesis. Median CSF CXCL13 concentration in ITAb-positive LNB patients was &gt; 500 times greater than in any other group.

Conclusions

Intrathecal CXCL13 and IgG production are closely interrelated. CXCL13 is disproportionately increased in “definite LNB,” defined as having demonstrable Borrelia-specific ITAb, but not “probable LNB,” without ITAb. This disproportionate increase may help identify patients with very early infection or those with active vs treated LNB, or may help to differentiate ITAb-defined active LNB from other neuroinflammatory disorders. However, its reported specificity is closely related to the diagnostic requirement for ITAb. It may add little specificity to the demonstration of a pleocytosis or increased overall or specific IgG production in the CSF.

Cerebrospinal fluid cytokines and chemokines in children with Lyme neuroborreliosis; pattern and diagnostic utility

BACKGROUND

Lyme neuroborreliosis (LNB) is characterized by cerebrospinal fluid (CSF) inflammation with several cytokines/chemokines and B-lymphocytes. Clinically, LNB in children may be difficult to discriminate from non-Lyme aseptic meningitis (NLAM). We aimed to identify CSF cytokine/chemokine patterns in children with LNB, NLAM and controls and elucidate the diagnostic value of these cytokines/chemokines alone or in combination to discriminate between LNB and NLAM.

METHODS

Children with symptoms suggestive of LNB were included prospectively and categorized as LNB, NLAM or controls (no pleocytosis). Cytokines/chemokines in CSF were measured by multiplex bead assays and levels were compared between the three groups by nonparametric statistical tests. Previous results from the same children on the established biomarker, CXCL13, were included in the statistical analyses. The diagnostic properties of cytokines/chemokines to discriminate between LNB and NLAM were determined by receiver operating characteristic curve analyses with estimates of area under curve (AUC). To explore diagnostic properties of combinations of cytokines/chemokines, prediction models based on logistic regression were used.

RESULTS

We included 195 children with LNB (n = 77), NLAM (n = 12) and controls (n = 106). Children with LNB had higher CSF levels of CCL19, CCL22 and CXCL13 compared to NLAM and controls, whereas INFγ was higher in NLAM than in LNB and controls. CXCL13 was the superior single cytokine/chemokine to discriminate LNB from NLAM (AUC 0.978). The combination CXCL13/CCL19 (AUC 0.992) may possibly improve the specificity for LNB, especially for children with moderate CXCL13 levels.

CONCLUSIONS

The intrathecal immune reaction in LNB is characterized by B cell associated chemokines. Whether the combination CXCL13/CCL19 further improves discrimination between LNB and NLAM beyond the diagnostic improvements by CXCL13 alone needs to be tested in new studies.

Guidelines for diagnosis and treatment in neurology - Lyme neuroborreliosis

Lyme borreliosis is the most common tick-borne infectious disease in Europe. A neurological manifestation occurs in 3–15% of infections and can manifest as polyradiculitis, meningitis and (rarely) encephalomyelitis.

This S3 guideline is directed at physicians in private practices and clinics who treat Lyme neuroborreliosis in children and adults.

Twenty AWMF member societies, the Robert Koch Institute, the German Borreliosis Society and three patient organisations participated in its development. A systematic review and assessment of the literature was conducted by the German Cochrane Centre, Freiburg (Cochrane Germany).

The main objectives of this guideline are to define the disease and to give recommendations for the confirmation of a clinically suspected diagnosis by laboratory testing, antibiotic therapy, differential diagnostic testing and prevention.

Comparison of Neuroborreliosis Between Children and Adults

BACKGROUND

Lyme neuroborreliosis (NB) is a tick-borne infectious disorder of the nervous system caused by Borrelia burgdorferi spirochetes. There are not many data available regarding the differences in the course of NB in children and adults. The aim of our study was to compare the clinical course of NB between children and adults.

METHODS

Retrospective analysis of medical documentation of 181 patients with NB was performed. The patients were divided into 2 groups: Group I: 57 children with NB; Group II: 124 adults with NB. Medical data, such as patients' age, sex, place of living (residence), time from a tick bite, subjective complaints, general examination results, laboratory parameters and treatment were analyzed.

RESULTS

In children, the most common symptoms were headache (89.5%), neck stiffness (64.9%) and nausea and vomiting (56.1%). In adults, the most common symptoms were headache (77.4%), facial nerve palsy (59.7%), neck stiffness (59.7%), vertigo (41.9%) and lumbosacral region pain (37.1%). Bannwarth's syndrome was observed in 10.5% of children and 36.3% of adults. In cerebrospinal fluid (CSF) in children, the pleocytosis at admission was higher than in adults, but protein concentration was significantly lower. There were no differences in percentage of mononuclear cells in CSF smear between the groups. In CSF examination after treatment, a decrease in pleocytosis and protein concentration was observed in both groups. Analysis of effectiveness of treatment mostly with third generation cephalosporins (defined as complete recovery) between the groups, calculated by the Kaplan-Meier method and compared with the use of the log-rank test, showed no significant differences between children and adults (log-rank P = 0.619).

CONCLUSIONS

In children, NB more frequently presented as meningitis, and in adults in the form of Bannwarth's syndrome. CSF pleocytosis in children with NB was higher than in adults, while the protein concentration in children was lower. Outcomes in children and adults were favorable and did not differ after standard NB treatment.

The B-lymphocyte chemokine CXCL13 in the cerebrospinal fluid of children with Lyme neuroborreliosis: associations with clinical and laboratory variables

Background: The B-lymphocyte chemokine CXCL13 is increasingly considered as a useful early phase diagnostic marker of Lyme neuroborreliosis (LNB). However, the large variation in level of CXCL13 in the cerebrospinal fluid (CSF) observed in LNB patients is still unexplained. We aimed to identify factors associated with the level of CXCL13 in children with LNB, possibly improving the interpretation of CXCL13 as a diagnostic marker of LNB. Methods: Children with confirmed and probable LNB were included in a prospective study on CXCL13 in CSF as a diagnostic marker of LNB. The variables age, sex, facial nerve palsy, generalized inflammation symptoms (fever, headache, neck-stiffness and/or fatigue), duration of symptoms, Borrelia antibodies in CSF, Borrelia antibody index (AI), CSF white blood cells (WBC), CSF protein and detection of the genospecies Borrelia garinii by PCR were included in simple and multivariable regression analyses to study the associations with the CXCL13 level. Results: We included 53 children with confirmed and 17 children with probable LNB. CXCL13 levels in CSF were positively associated with WBC, protein and Borrelia antibodies in CSF in both simple and multivariable analyses. We did not find any associations between CXCL13 and age, sex, clinical symptoms, duration of symptoms, AI or the detection of Borrelia garinii. Conclusions: High levels of CSF CXCL13 are present in the early phase of LNB and correlate with the level of CSF WBC and protein. Our results indicate that CSF CXCL13 in children evaluated for LNB can be interpreted independently of clinical features or duration of symptoms.

Lyme neuroborreliosis and bird populations in northern Europe

Many vector-borne diseases are transmitted through complex pathogen-vector-host networks, which makes it challenging to identify the role of specific host groups in disease emergence. Lyme borreliosis in humans is now the most common vector-borne zoonosis in the Northern Hemisphere. The disease is caused by multiple genospecies of Borrelia burgdorferi sensu lato bacteria transmitted by ixodid (hard) ticks, and the major host groups transmit Borrelia genospecies with different pathogenicity, causing variable clinical symptoms in humans. The health impact of a given host group is a function of the number of ticks it infects as well as the pathogenicity of the genospecies it carries. Borrelia afzelii, with mainly small mammals as reservoirs, is the most common pathogen causing Lyme borreliosis, and it is often responsible for the largest proportion of infected host-seeking tick nymphs in Europe. The bird-borne Borrelia garinii, though less prevalent in nymphal ticks, is more likely to cause Lyme neuroborreliosis, but whether B. garinii causes disseminated disease more frequently has not been documented. Based on extensive data of annual disease incidence across Norway from 1995 to 2017, we show here that 69% of disseminated Lyme borreliosis cases were neuroborreliosis, which is three times higher than predicted from the infection prevalence of B. garinii in host-seeking ticks (21%). The population estimate of migratory birds, mainly of thrushes, explained part of the annual variation in cases of neuroborreliosis, with a one-year time lag. We highlight the important role of the genospecies' pathogenicity and the host associations for understanding the epidemiology of disseminated Lyme borreliosis.

Identification of a novel variant of Golli myelin basic protein BG21 in the uniquely neuroprotective white-footed mouse

The myelin basic protein (MBP) gene is a complex gene which codes for several distinct forms of MBP. The various forms of MBP are functionally involved in the development of the nervous system, T-cell regulation, and myelination. Several neurological disorders have been linked to MBP abnormality, further demonstrating its functional significance in the nervous system. The white-footed mouse (Peromyscus leucopus) exhibits profound neuroprotective characteristics, is asymptomatic to various disease-states, and has a lifespan twice that of the house mouse (Mus musculus). We used M. musculus mouse MBP as a reference to explore MBP in P. leucopus mice. Through genetic and downstream proteomic data analysis, we identified a novel variant of the BG21 isoform of MBP in P. leucopus mice. Variation in this isoform is present at the genetic level between the two species of mice. Our results show differences within the open reading frame of the transcripts accompanied by corresponding differences in protein structure prediction. These data introduce the potential of MBP variation as one of many causal variables contributing to the unique presentation of enhanced neuroprotection and longevity in P. leucopus mice.